High performance aircraft now are being manufactured with extensive use of composite material made up of fibers of a material, such as graphite, embedded within a plastic. It becomes difficult to secure fasteners to this material because of its lower resistance to compression loads than metal, and such factors as notch sensitivity. The problem is made more severe for fasteners permanently attached to the aircraft structure with provision for limited floating movement to facilitate engagement by a mating threaded member. In many such cases a nut portion of the fastener may become damaged in service so that it should be removed from the assembly and replaced. Conventional fasteners are not suitable for this purpose when associated with composite aircraft structures.